My name is Legion, for we are many.
I SAY HELL NO
Armor Abilities as a general idea, yes, but Armor Lock doesn't belong in the game. Since in Halo you have Mjolnir armor and energy shields, and weapons have different effects against shielding and health, it's already a slower-paced shooter than some other games - though I have nothing wrong with that. Armor Lock, however, forces players to waste time waiting for the guy to unlock and thus slows down a multiplayer match even more.
Just try to play competitively with a Needle Rifle/DMR/Assault Rifle/Pistol against an enemy team containing 4+ Armor Lockers, and you'll see what I mean.